Chapter 12
The annual effective dose limit for individual members of the general population not occupationally exposed is ___________ for continuous or frequent exposures from artificial sources other than medical irradiation and natural background and ____________ for infrequent annual exposure.
1 mSv (0.1 rem), 5 mSv (0.5 rem)
3 mSv (0.3 rem), 7 mSv (0.7 rem)
5 mSv (0.5 rem), 9 mSv (0.9 rem)
50 mSv (5 rem), 25 mSv (2.5 rem)
1 mSv (0.1 rem), 5 mSv (0.5 rem)
Which part(s) of a diagnostic x-ray unit should a radiographer avoid touching while a radiographic exposure is in progress?
Control panel
Exposure switch
Kilovoltage control on the control panel
Tube housing, collimator, and high-tension cables
Tube housing, collimator, and high-tension cables
A spot film device protective curtain or sliding panel of a minimum thickness of 0.25-mm lead equivalent should normally be positioned between the fluoroscopist and the patient to intercept which of the following types of radiation?
Primary radiation
Scattered radiation above the tabletop
Exit or image formation radiation
Direct radiation
Scattered radiation above the tabletop
Which of the following adjustments in technical exposure factors decreases the production of scattered radiation?
Decrease kVp and increase mAs in compensation
Decrease kVp and decrease mAs
Increase kVp and decrease mAs in compensation
Increase kVp and increase mAs
Increase kVp and decrease mAs in compensation
Which of the following x-ray procedures increases the radiographer’s risk of exposure to ionizing radiation?
1. Mobile C-arm fluoroscopy
2. Interventional procedures that use high-level-control fluoroscopy
3. Mobile radiographic examinations
1 and 2 only
1 and 3 only
2 and 3 only
1, 2, and 3
1, 2, and 3
While standing behind the control-booth barrier, a radiographer makes a radiographic exposure. The x-rays scattered from the patient’s body should ________ behind the control-booth barrier.
not have enough energy remaining that will reach
scatter only once before reaching any area
scatter a minimum of two times before reaching any area
scatter a minimum of ten times before reaching any area
scatter a minimum of two times before reaching any area
When the time spent in a higher-radiation area is reduced or limited, occupational exposure:
is also reduced
is increased slightly
remains the same
is increased considerably
is also reduced
Which of the following is another term for use factor (U)?
Workload factor
Occupancy factor in controlled and uncontrolled areas
Beam direction factor
Protective barrier thickness consideration factor
Beam direction factor
In terms of occupational risk, radiography may be compared with the occupational risk associated with:
extremely hazardous industries
other industries considered reasonably safe, such as government or trade
a nuclear war
a radiation accident, such as the Chernobyl nuclear power plant disaster
other industries considered reasonably safe, such as government or trade
______ is the radiation output weighted time that the unit is actually delivering radiation during the week.
Control designation
Occupancy
Use factor
Workload
Workload
Secondary radiation includes _____ radiation.
1. leakage
2. primary
3. scatter
1 and 2 only
1 and 3 only
2 and 3 only
1, 2, and 3
1 and 3 only
If the intensity of the x-ray beam is inversely proportional to the square of the distance from the source, how does the intensity of the x-ray beam change when the distance from the source of radiation and a measurement point is tripled?
It increases by a factor of 3 at the new distance.
It increases by a factor of 9 at the new distance.
It decreases by a factor of 9 at the new distance.
It decreases by a factor of 3 at the new distance.
It decreases by a factor of 9 at the new distance.
Whenever scattered radiation decreases, the radiographer’s exposure:
decreases
increases slightly
increases considerably
remains the same
decreases
During which of the following x-ray examinations should a radiographer always wear a thyroid shield?
Fluoroscopy and special procedures
Routine mobile radiographic procedures
General diagnostic radiographic procedures performed in an x-ray room
Digital radiography procedures and computed radiography procedures
Fluoroscopy and special procedures
What is the term for the proportional amount of time during which the x-ray beam is energized or directed toward a particular barrier?
Occupancy factor
Workload factor
Distance factor
Use factor
Use factor
Diagnostic imaging personnel receive the highest occupational exposure during which of the following procedures?
1. Fluoroscopy
2. Mobile radiography
3. Special procedures
1 only
2 only
3 only
1, 2, and 3
1, 2, and 3
To ensure that the lifetime risk of occupationally exposed persons remains acceptable, the lifetime effective dose in mSv should not exceed _____ occupationally exposed person’s age in years.
the
5 times
10 times
20 times
10 times
If the peak energy of the x-ray beam is 100 kVp, a protective lead apron must be the equivalent of which of the following measures?
0.25-mm thickness of lead
0.5-mm thickness of lead
1.0-mm thickness of lead
1.5-mm thickness of lead
0.25-mm thickness of lead
Protective eyeglasses with optically clear lenses should contain a minimal lead equivalent protection of _____ mm.
0.15
0.25
0.35
0.50
0.35
For C-arm devices with similar fields of view, the dose rate to personnel located within a meter of the patient is _______ fluoroscopy.
comparable to that of routine
far greater than the dose rate of routine
significantly less than the dose rate of routine
comparable to that of high-level-control
comparable to that of routine
When a radiologic technologist declares her pregnancy to her employer, which of the following is appropriate?
Her employer terminates her employment until after her child is born.
She is able to continue her employment but is not permitted to perform any radiologic procedures during the remainder of her pregnancy.
Her employer requires her to take a leave of absence until after the completion of the first trimester of the pregnancy and then return to her normal duties.
She continues to perform her duties without interruption of employment, provided that she has received radiation safety counseling and follows established radiation safety practices.
She continues to perform her duties without interruption of employment, provided that she has received radiation safety counseling and follows established radiation safety practices.
The maximum weekly permitted equivalent dose for a controlled area must not exceed _____ microsievert (_____ mrem).
1000; 100
100; 10
20; 2
2; 0.2
1000; 100
When doors to radiographic and fluoroscopic rooms are closed during radiation exposures, a substantial degree of protection is provided for persons in areas adjacent to the room door. This is because in most facilities room doors have attenuation for diagnostic energy x-ray equivalent to that provided by a _____ inch of lead.
1/2
1/4
1/16
1/32
1/32
Who should determine the exact shielding requirements for a particular imaging facility?
Administrator of the facility
Medical physicist
Radiologist
Radiographer
Medical physicist
Because occupational exposure of the radiographer can be kept as low as reasonably achievable (ALARA) through individual monitoring and other protective measures and the use of protective devices and because exposure from radiation-related jobs will not alter the ____________, radiation workers may receive a larger equivalent dose than members of the general population.
mean glandular dose
genetically significant dose
bone marrow dose
tissue tolerance dose
genetically significant dose